title: Assessing the ecotoxicologic hazards of a pandemic influenza medical response.
abstract: BACKGROUND
  The global public health community has closely monitored the unfolding of the 2009 H1N1 influenza pandemic to best mitigate its impact on society. However, little attention has been given to the impact of this response on the environment. Antivirals and antibiotics prescribed to treat influenza are excreted into wastewater in a biologically active form, which presents a new and potentially significant ecotoxicologic challenge to microorganisms responsible for wastewater nutrient removal in wastewater treatment plants (WWTPs) and receiving rivers.
  
  
  OBJECTIVE
  We assessed the ecotoxicologic risks of a pandemic influenza medical response.
  
  
  METHODS
  To evaluate this risk, we coupled a global spatially structured epidemic model that simulates the quantities of antivirals and antibiotics used during an influenza pandemic of varying severity and a water quality model applied to the Thames catchment to determine predicted environmental concentrations. An additional model was then used to assess the effects of antibiotics on microorganisms in WWTPs and rivers.
  
  
  RESULTS
  Consistent with expectations, our model projected a mild pandemic to exhibit a negligible ecotoxicologic hazard. In a moderate and severe pandemic, we projected WWTP toxicity to vary between 0-14% and 5-32% potentially affected fraction (PAF), respectively, and river toxicity to vary between 0-14% and 0-30% PAF, respectively, where PAF is the fraction of microbial species predicted to be growth inhibited (lower and upper 95% reference range).
  
  
  CONCLUSIONS
  The current medical response to pandemic influenza might result in the discharge of insufficiently treated wastewater into receiving rivers, thereby increasing the risk of eutrophication and contamination of drinking water abstraction points. Widespread drugs in the environment could hasten the generation of drug resistance. Our results highlight the need for empirical data on the effects of antibiotics and antiviral medications on WWTPs and freshwater ecotoxicity.
authors.affiliation: Centre for Ecology and Hydrology, Wallingford, Oxfordshire, United Kingdom. acsi@ceh.ac.uk
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Singer
authors.forename: Vittoria
authors.initials: V
authors.lastname: Colizza
authors.forename: Heike
authors.initials: H
authors.lastname: Schmitt
authors.forename: Johanna
authors.initials: J
authors.lastname: Andrews
authors.forename: Duygu
authors.initials: D
authors.lastname: Balcan
authors.forename: Wei E
authors.initials: WE
authors.lastname: Huang
authors.forename: Virginie D J
authors.initials: VD
authors.lastname: Keller
authors.forename: Alessandro
authors.initials: A
authors.lastname: Vespignani
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Williams
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis; D000998:Antiviral Agents / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D006801:Humans; D007251:Influenza, Human; D058873:Pandemics; D011634:Public Health; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000900:Anti-Bacterial Agents; D000998:Antiviral Agents; D014874:Water Pollutants, Chemical